Tool for adjusting relay contacts



Aug. 5, 1969 R. K. WILSON TOOL FOR ADJUS TING RELAY CONTACTS 2 Sheets-Sheet 1 Filed Jan. 2, 1968 M/l/ENTOR R. K WILSON ATTORNEY R. K. WILSON TOOL FOR ADJUSTING RELAY CONTACTS Aug. 5, 1969 2 Sheets-$heet 2 Filed Jan. 2, 1968 United States Patent US. Cl. 72452 8 Claims ABSTRACT OF THE DISCLOSURE An adjusting tool is disclosed wherein a rotating gripping member deforms a contact spring in response to sliding movement of a cam member. Rotation of the cam member, in turn, is induced by rotating the cam member against a handle.

BACKGROUND OF THE INVENTION Field of the invention This invention relates generally to a metal deforming tool. More particularly, the invention pertains to a tool for adjusting resilient contact springs such as those commonly found in a relay.

Description of the prior art Many relays have contact springs which are arranged in pairs and in which the contact springs in each pair are normally biased toward each other so as to establish a desired contact force. A typical example is relays of the wire spring type which are widely used in telephone systems. In wire spring relays, the contact force is established during manufacture; i.e., by deforming a portion of the moving part of one or the other of the two contact springs in a pair. Although intended to last for the life of the relay, the contact force often is accidentally changed in service. When such a change occurs, either the relay must be replaced or the correct contact force must be reestablished.

A principal cause of changes in contact force are accidental bends which modify the angle at which the contact springs project from their supporting structure. Heretofore no specific tool was available to redeflect bent contact springs. As a result, tools were used which were designed for other purposes, such as pliers or screwdrivers. Such tools, however, are awkward and inconvenient for this purpose and oftentimes cause additional damage when used.

SUMMARY OF THE INVENTION In a preferred embodiment of this invention a contact spring adjusting tool comprises a handle having a bearing surface, a cam member which slides on a shaft in response to pressure by the bearing surface on the handle, and a gripping member which locks on a contact spring and induces deformation therein in response to sliding movement of the cam member.

DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view of a portion of a wire spring relay in which an adjusting tool made in accordance with this invention is shown in the operating condition;

FIG. 2 is a side elevation view of the adjusting tool shown in FIG. 1 with portions broken away and in which the tool is shown in the unoperated condition;

FIG. 3 is another side elevation view of the adjusting tool shown in FIG. 1 and portrays the tool in the operated condition;

FIG. 4 is an enlarged perspective view of a portion of the adjusting tool and relay shown in FIG. 1 and portrays the tool in the unoperated condition;

3,459,039 Patented Aug. 5, 1969 FIG. 5 is another enlarged perspective view of a porhem of the adjusting tool and relay shown in FIG. 1 and portrays the tool in the operated condition.

DETAILED DESCRIPTION Referring now to FIG. 1, an adjusting tool 10 is illustrated together with a section of a relay 40-. The tool 10 comprises a shaft 11, a handle 12, a gripping member 13, and a cam member 14 while the section of the relay 40 illustrated comprises a support 41, contact springs 42 and 43, a guide block 44 and a card 45.

The shaft 11 is made of a rigid material such as brass and is conveniently cylindrical in shape. One end has a hole for accepting a lOCking pin and the other end, as best seen in FIG. 4, terminates in a blade portion 15.

The handle 12 is made of a rigid material such as brass and includes an axial hole for accommodating the shaft 11. One end of the handle 12 includes a hole for accommodating a locking pin 16. As can be seen from FIGS. 1 and 2, the locking pin 16 extends through the holes in the handle 12 and the shaft 11 and holds the two firmly together. As shown in FIG. 2, the other end of the handle 12 terminates in a bearing surface 17. For reasons to be explained later, the bearing surface 17 is disposed on a bias with respect to a plane orthogonal to the axes of the shaft 11 and handle 12.

The gripping member 13 is made of a rigid material such as brass and, as best seen in FIG. 4, includes a slot 18 and a groove 19. The slot 18- accommodates the blade portion 15 of the shaft 11 while the groove 19 is arranged to accept a contact spring. The blade portion 15 is held in the slot 18 by a pin 21. The fit between the blade portion 15 and the slot 18 is loose; consequently, the gripping jaw 13 is free to rotate. Finally, the end of the gripping member 13 which contains the slot 18 also includes a cam ming surface 22. The caming surface 22 cooperates with the cam member 14 to impart rotational movement to the gripping member 13.

The cam member 14 is made of a rigid material such as brass and includes an axial hole which passes through its length. The hole accommodates the shaft 11 and is slightly oversized so that the cam member 14 can slide freely. As best seen in FIGS. 4 and 5, one end of the cam member 14- terminates in a bearing surface 24. As shown in FIGS. 1, 2 and 3, the other end of the cam member 14 is conveniently enlarged to form a finger grip 25 which terminates in a camming surface 26. The camming surface 26 is disposed on a bias and is cut so that it assumes a contiguous position with respect to the bearing surface 17 when the camming member 14 is rotated into a predetermined position. Thus, when the cam member 14- is rotated out of its predetermined position, the camming surface 26 and the bearing surface 17 press against each other and force the cam member 14 to slide along the shaft 11 away from the handle 12.

As the cam 14 slides along the shaft 11 and away from the handle 12, the bearing surface 24 engages the camming surface 22 on the gripping member 13. As the cam member 14 continues to slide, the action between the camming surface 22 and the bearing surface 24 causes the gripping member 13 to rotate. As shown in FIG. 5, the rotation of the gripping jaw 13 is the mechanism by which the contact spring of a relay is bent to reestablish contact force.

Turning to the portion of the relay 40 shown in FIG. 1, the contact springs 42 and 43 are typical. Both are mounted by one end inthe support 41. The contact spring 42 contains a deforming bend which urges the free end toward the contact spring 43 in the vicinity of the card 45. The card 45, however, includes means for keeping the two contact springs apart when it is in the position shown. The

guide block 44 maintains the two contact springs 42 and 43 in a common plane.

Clearly, the angle at which the contact springs 42 and 43 extend out of the support 41 controls the amount of contact force available from the deforming bend. If, for example, one of the contact springs is accidentally bent so that the new angle it assumes With respect to the support 41 directs it closer to the other contact spring, the contact force will increase. Conversely, if an accidental bend increases the angle between the contact springs, the contact force will decrease. In either case, the original contact force can only be reestablished by returning the contact spring to its unbent position.

In the situation illustrated in FIGS. 1 and 4, the contact spring 42 has been accidentally bent. In order to return it to its unbent position, the tool is inserted into the front of the relay 40; e.g., through the card 45 as shown in FIG. 1. The tool 10 is inserted until the gripping member 13 is adjacent to the support 41. Thereafter, as best seen in FIG. 4, the groove 19 is slipped over the contact spring 42. Next, the cam member 14 is rotated on the shaft 11. Rotation is continued until, as shown in FIG. 3, the cam member 14 slides away from the handle 12 and the bearing surface 24 engages the camming surface 22 on the gripping member 13. Thereafter, continued rotation forces the gripping member 13 to rotate. As shown in FIG. 5, When the gripping member 13 rotates, the groove 19 defiects the contact spring 42. Deflections of the contact spring 42 are made in small increments and are continued until the proper contact force is reestablished.

The bias out between the handle 12 and the cam member 14 permits the bending increment to be kept small. As a result, contact force is quickly reached but not exceeded. Nevertheless, the bias cut is easily fabricated. Thus, in accordance with this invention, precise adjustments are easily obtained from a tool that is simple to use and easy to make.

In conclusion, the embodiment disclosed herein comprises only one aspect of this invention. It is clear, however, that many other embodiments which fall within the spirit and scope of the invention will occur to others skilled in the art.

What is claimed is:

1. A tool for adjusting contact springs, said tool comprising:

a shaft;

a handle mounted on one end of said shaft and having first bearing means at one end;

an elongated cam member mounted freely on said shaft and including first camming means on one end and second bearing means on the other end, said first camming means being in contact with said first hearing means and arranged to impart a sliding movement to said cam member when said cam member is rotated; and

gripping means for deforming a contact spring in response to sliding movement of said cam member, said gripping means including second camming means for cooperating with said second bearing means.

2. An adjusting tool in accordance with claim 1 wherein said gripping means is pin-mounted to said shaft at one end and including grasping means for gripping a contact spring at the other end.

3. An adjusting tool in accordance with claim 2 wherein said grasping means comprises a groove.

4. An adjusting tool in accordance with claim 2 wherein said second camming means comprises a curved side of said gripping means.

5. An adjusting tool in accordance with claim 1 wherein said cam member is disposed on said shaft between said handle and said gripping means.

6. An adjusting tool in accordance with claim 1 wherein said cam member includes a raised finger grip.

7. An adjusting tool in accordance with claim 1 wherein said first bearing means comprises a surface on said handle cut on a bias to lie in a plane disposed at an angle from a plane orthogonal to the axis of said shaft and said first camming means comprises a surface on said cam member cut on a bias to lie in a plane disposed at an angle from a plane orthogonal to the axis of said shaft.

8. An adjusting tool in accordance with claim 7 wherein the angles between the planes containing said surfaces are such that said surfaces become contiguous when said cam member is rotated to a preselected position.

References Cited UNITED STATES PATENTS 1,301,185 4/1919 Sorensen 81-3 1,711,692 5/1929 Robinson 72-458 1,712,573 5/ 1929 Loveridge 72-458 2,095,137 10/1937 Johnson 81-53 2,740,435 4/ 1956 Pritts -147 2,837,813 6/1958 Anselmo 29-227 3,303,685 2/1967 Conran 72-386 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US. Cl. X.R. 72-458; 81-3 

